Although polio has largely receded from public health concerns in the U.S., where it was eliminated more than four decades ago, strains of the virus that causes the disease still circulate in parts of Europe, Asia and Africa. At home, measles outbreaks have recently been reported in Pennsylvania, Virginia and Utah, pushing the total number of cases in the U.S. during 2026 to more than 2,220—already more than last year’s count, according to the Centers for Disease Control and Prevention.

“More than anything, it’s a good reminder that staying up to date on vaccinations is critical to staying safe and healthy while traveling,” said Michael Ben-Aderet, MD, associate director of Hospital Epidemiology at Cedars-Sinai.

The Cedars-Sinai Newsroom spoke with Ben-Aderet about what travelers should know about polio and measles and how to stay safe this summer.

Where does polio still exist?

Polio is caused by a highly contagious virus that has essentially been eliminated from most of the world through vaccination. Wild strains still persist in a handful of countries, including Afghanistan and Pakistan, which means the vast majority of international travelers are at relatively low risk, particularly if they’ve been vaccinated. In recent years, roughly 30 countries in Africa, Europe and Asia, including the U.K. and Germany, have shown signs of the virus circulating. However, those signs are not necessarily tied to outbreaks. For example, public health officials in the U.K. have detected the virus in wastewater tests, which likely points to some degree of asymptomatic polio.

How does polio spread?

The poliovirus typically spreads when an infected person doesn’t wash their hands after using the restroom and contaminates water, food or other surfaces that others touch. It usually causes a mild illness that most people recover from quickly. What makes polio historically frightening is that a small percentage of infections can progress to paralysis, typically affecting the legs and feet, when the virus invades the nervous system. That’s why vaccination is so important. It has essentially eliminated that fear in populations where immunization rates are high.

How big of a threat is polio to international travelers?

Almost everyone in the U.S. received the polio vaccination series as a child. For vaccinated travelers, the risk is minimal. For older adults concerned that their immunity may have waned over the years, a booster is worth considering before visiting regions where polio transmission remains a possibility. The polio vaccine has minimal side effects, so there is little harm in getting the vaccine. You won’t receive the full benefit of immunity until four weeks after vaccination, but you’ll start receiving some protection immediately.

Where is measles a concern?

Measles is, in many ways, a more immediate risk to summer travelers, especially in crowded or enclosed spaces. It’s far more contagious, spreading through airborne particles from an infected person’s cough or sneeze, and it can stay in the air for up to two hours after that person leaves.

Recent clusters have emerged in parts of California, Texas and Oklahoma, and the largest outbreaks have been reported in India, Bangladesh, Yemen, Mexico and Pakistan. Measles outbreaks are happening in multiple countries throughout the world. You could try to avoid known measles outbreaks as you travel, but the chance of encountering someone with measles has risen as fewer people get vaccinated, and you don’t know when you’ll be exposed.

How protected are those who have been vaccinated?

Most fully vaccinated individuals are well protected for life. Adults who are uncertain whether they ever received the two doses of the MMR vaccine, which protects against measles, mumps and rubella, should consider getting at least one dose. Adults at high risk should consider two doses at least 28 days apart. Children are recommended to receive two doses: one at 12 to 15 months and one at 4 to 6 years old. Babies 6 to11 months old should get one dose before they travel and two more doses after their first birthday.

It’s always a good idea to check your vaccination records and to consult your primary care provider or a travel medicine clinic four to six weeks before traveling abroad.

Read more from Cedars-Sinai Stories and Insights: 8 Expert Tips to Avoid Getting Sick When You Travel

Pimentel points out that the days between Thanksgiving and New Year’s are among the riskiest for food poisoning, especially as large meals, buffets and leftovers become part of the festivities. Each year, about 48 million Americans—roughly 1 in 6—get sick from foodborne illnesses, leading to an estimated 128,000 hospitalizations and 3,000 deaths, according to the Centers for Disease Control and Prevention.

Pimentel and Cedars-Sinai clinical dietitian Albert Abayev, RD, who works with patients undergoing weight loss surgery and general surgery, serve up answers to common holiday food safety questions.

What new insights have emerged in recent years about food poisoning—its causes, risks and prevention?

Pimentel: Foodborne illness continues to result from contamination with bacteria such as E. coli, Salmonella, Shigella or Campylobacter jejuni. Improper handling remains a major source of contamination. Foods left out for hours—common during buffets and large gatherings—create ideal conditions for bacterial growth.

Abayev: Many holiday-related food safety issues stem from outdated traditions or rushed environments. Long stretches of food left out on counters, undercooked poultry or stuffing, crowding the refrigerator, thawing meats on the counter, and multitasking that can lead to cross contamination are among the most frequent problems.

How long does it take to get food poisoning—and is the last meal always to blame?

Pimentel: Symptoms do not always appear immediately. Certain infections may take up to 48 hours to incubate. When determining the likely source, consider foods eaten in the prior two days and whether others who shared them also became ill.

How long does food poisoning usually last—and is it contagious?

Pimentel: Most cases resolve within a few days. E. coli often clears quickly, while Salmonella and Campylobacter may last a week or longer. Foodborne illness is not contagious like a virus, but contamination can occur if a sick person prepares food for others. Those with any symptoms should avoid preparing meals until fully recovered.

What are the biggest food safety mistakes people make in holiday kitchens?

Abayev: Allowing food to sit at room temperature for extended periods is the most common issue. Once food has been out for more than two hours, bacteria grow quickly. Undercooking turkey, stuffing and casseroles is another frequent problem; all dishes should reach 165 degrees Fahrenheit. Cross contamination, refrigerator overcrowding and improper thawing also add to the risk.

How reliable are the 'smell test' or 'eye test' when judging leftovers, and how long do leftovers stay safe?

Abayev: Appearance and smell are not reliable indicators of safety. Many harmful bacteria do not alter a food’s odor or color. Leftovers should be refrigerated within two hours, used within three to four days and reheated to 165 degrees. Also, freezing the food preserves quality for several months.

How should people with digestive conditions—or those using GLP-1 medications for weight loss—approach holiday meals safely?

Pimentel: Individuals with irritable bowel syndrome, inflammatory bowel disease or other chronic gastrointestinal conditions are more susceptible to foodborne illness, and an infection can worsen symptoms or trigger flares. Careful food handling, thorough cooking and choosing low-risk foods are especially important.

Abayev: GLP-1 users on weight management programs may experience slower stomach emptying, making heavy holiday foods more likely to cause discomfort. Smaller portions, slower eating, prioritizing protein and staying upright after meals can help. Because food remains in the stomach longer, contamination may result in stronger symptoms.

What should people do to recover from food poisoning?

Pimentel: Recovery starts with hydration. Small, frequent sips of water, electrolyte drinks or broth help replace losses. Bland foods like toast, rice, bananas or broth-based soups can be added as symptoms improve. Medical care is appropriate if symptoms last more than a couple of days or if there is high fever, blood in the stool or signs of dehydration.

What is one of the biggest food safety concerns this year?

Pimentel: Improved monitoring has reduced contamination in meat but produce now poses growing concern. Field conditions may limit workers’ access to proper hygiene, and many vegetables are eaten raw, eliminating the safety benefit of cooking.

What is the most important takeaway for holiday hosts and guests?

Abayev: Temperature control is the foundation of food safety. Hot foods should stay hot, cold foods should stay cold and leftovers should be refrigerated promptly.

Pimentel: Better safe than sorry; no one wants a side of food poisoning with their holiday meal.

Read more on the Cedars-Sinai Blog: Weight-Loss Drugs—What to Know Now

Shervin Rabizadeh, MD, chair of Pediatrics at Cedars-Sinai Guerin Children’s, says vaccinating your child helps protect the whole family, including elderly grandparents.

“Vaccines are critical in preventing transmission of the virus that causes COVID-19, especially during upcoming holiday gatherings,” Rabizadeh  said. “You want to prevent and stop passage of the virus between individuals, and kids are often the vectors. They are the petri dishes that pass things on, so this [vaccination] is a great means of prevention.”

At a recent Cedars-Sinai COVID Clinic, healthcare workers distributed free Pfizer 2023-2024 COVID-19 vaccines to children 6 months to 4 years old and Pfizer updated COVID-19 vaccines to children 5 to 11 years old.

Alison Chen’s two children were among the more than 120 who joined the pop-up clinic.

“We’re traveling to see family for Christmas, and airplanes are a bit nerve-wracking,” Chen said. “We also want to make sure we’re as safe as possible before seeing our grandparents.”

Priya Soni, MD, Cedars-Sinai pediatric infectious disease specialist, said there are many important reasons children should be vaccinated against COVID-19.  

“While many children have milder infections than adults, some children develop severe lung infections from COVID-19 that require hospitalization,” Soni said. “Children also can develop bacterial pneumonia after recovering from COVID-19. Another complication is multisystem inflammatory syndrome in children [MIS-C], which can require care in an intensive care unit [ICU].”

During the COVID Clinic, some young children cried as they received their vaccines, but the parents, including Arturo Garcia, were smiling. Garcia brought his 19-month-old daughter, Anna Sofia, to the clinic.  

“It’s important to keep our children safe and healthy,” Garcia said. “It’s the best gift we can give our children.” 

Read more on the Cedars-Sinai Blog: Here Are the Back-to-School Vaccinations Your Kids Need

Based on results from new clinical trials, the Centers for Disease Control and Prevention (CDC) recently issued proposed guidelines for using doxycycline to reduce the risk of a chlamydia or syphilis—and possibly gonorrhea—infection among sexually active adults. Experts say new preventive approaches are critical to control the widening STI epidemic, fueled in part by the disruption in healthcare services during the height of the COVID-19 pandemic.

“Even before COVID started, we had seen a significant increase in STDs [sexually transmitted diseases], both internationally and here locally in California,” said Christopher Foltz, MD, an infectious disease specialist at Cedars-Sinai. “Syphilis has been climbing at the highest rate with a significant increase among pregnant women and men who have sex with men.” 

Growing Problem

Syphilis cases among men who have sex with men rose 7% from 2020 to 2021, according to the CDC. Syphilis rates among women jumped 55.3% from 2020 to 2021, and 217.4% from 2017 to 2021, which has led to the birth of more babies with the disease.

People with syphilis often don’t have symptoms, Foltz said, and when they finally visit a doctor, they may have been infected for months—or even years—without knowing it. Undiagnosed long-term infections can lead to permanent complications, including blindness and permanent neurologic damage.

“That's what we're trying to prevent—these kinds of catastrophic long-term complications from undiagnosed STIs,” Foltz said. “If we can prevent infections with a relatively safe and easy-to-take antibiotic, the overall number of new infections will ultimately decrease.”

Old Drug, New Use

Doxycycline has long been a go-to treatment for acne, skin infections, illnesses spread by tics and pneumonia. The drug had been on the radar of physicians treating STIs for years, but previous clinical trials hadn’t shown it would be effective as a preventive therapy. Physicians have become increasingly hesitant to prescribe antibiotics when they’re not needed amid a rise in antibiotic-resistant bugs.

“Bacteria can figure out how to avoid being killed by antibiotics,” explained clinical pharmacist Greg Marks, PharmD, coordinator of the Antimicrobial Stewardship program at Cedars-Sinai Medical Center, which closely tracks the use of antibiotics in the hospital. “In general, the more we use antibiotics, the more concerned we are about resistance.”

But new trial results showed doxycycline could be an effective new tool to limit the spread of syphilis and chlamydia if taken as a single 200-milligram dose within 72 hours after unprotected sex, Marks said. Using doxycycline to prevent gonorrhea showed some promise but yielded mixed results.

Only one dose of the antibiotic is necessary in a three-day period to help avoid these bacterial infections, even if having sex with multiple partners. The strategy, dubbed “Doxy on Demand” or “Doxy-PEP” (post-exposure prophylaxis), is similar to taking the morning-after pill to prevent pregnancy after unprotected sex. But this new treatment isn’t a reason to ditch condoms.

“This by no means is a way to offset the use of condoms,” Foltz cautioned. “We absolutely encourage condom use to prevent against other STDs and HIV [human immunodeficiency virus] as an added barrier of protection for prevention.”

Foltz said the people most likely to benefit from this new strategy are those who have had STDs recently, those taking HIV medications or medications to prevent the spread of HIV, and members of the LGBTQ+ community, which tends to experience higher rates of certain STIs.

Pregnant women should generally avoid the drug, Marks said, as well as people allergic to tetracyclines, a class of antibiotics. He and Foltz encouraged patients to speak with a physician about whether doxycycline might be right for them.

“If you're actively having sex and not using condoms 100% of the time, which is the reality out there, this strategy could be appropriate for you,” Foltz said. “It comes down to each person’s individual risk level, something that you should discuss with your physician.”

Read more on the Cedars-Sinai Blog: Gaining Ground on HIV/AIDS

What can you do to prevent ticks bites?

"There are several precautions to take before you hit the trails that can prevent bites, such as:

• Wear long-sleeved shirts and long pants. 
• Tuck the bottom of your pants into your boots or socks.  
• Apply tick repellent to clothing. Products with DEET will repel ticks and products with permethrin will kill ticks on contact.
• Avoid hiking in tall grass or heavily wooded areas because ticks tend to live and thrive in those areas.
• Try to hike in the center of the trail to reduce contact with ticks.

How do you check for ticks when you get home?

“The best place to inspect for ticks is in the shower. When you are inspecting your child check around the ears, near the hair line, under the arms, behind the legs and even inside the belly button because ticks like those crevices.”

How do you remove a tick?

“To remove a tick use a tweezer, and you want to apply the force of the tweezer at the base of the tick and  pull up. You don’t want to twist the tick off because you can leave parts of the tick inside embedded in the skin. If a tick is noticed within 24-hours of the hike or bite, and you are able to successfully remove it, the risk of transmission of any tickborne disease is very, very low.”  

What is the risk of Lyme disease?

“Thankfully, in Southern California, the risk of Lyme disease is much, much less than in other parts of the country, particularly in the Northeast. Most of the Lyme disease that we see here in Southern California actually comes from when a child or patient has traveled from the East Coast and they've been hiking there or have been in a summer camp, and they come back and they contracted Lyme disease from their exposure from these Lyme-endemic states in the Northeast.

“Ticks that carry the bacteria that cause Lyme disease can also carry other bacteria and cause infections known as Anaplasmosis and Ehrlichiosis. Symptoms of both can include fever, muscle aches, weakness and headache. Unlike Lyme disease, a rash is not as common. Symptoms usually occur one to two weeks after a bite from an infected tick. In both cases, they can be treated with proper antibiotics. Not every bite from an infected tick however, results in an infection.” 

What other bites do hikers need to watch out for?

"It's very important for parents to also understand that ticks are not the only thing that can bite you when you're out hiking in Southern California. We also often see infections that are caused by fleas. We call this "flea-borne typhus” and it is caused by a Rickettsial bacteria causing infection.  Animals that can carry these infected fleas include cats, wild possums, rats and mice. The infection is usually characterized by high grade fever, a rash as well as a bad headache. It's very important for parents to be aware that if their child goes hiking and has these symptoms, that could be from exposure to an infected flea.

Overall, the best advice is prevention, by wearing the right clothing and using repellents. But if you suspect someone in your family has a flea or tick infection, it’s important to let your doctor know you’ve been hiking to get the proper diagnosis."

Read more on the Cedars-Sinai Blog: Should You Exercise on the Beach?

Older women are among the most susceptible to developing UTIs, an infection of the bladder and urethra that causes urinary urgency and pain. UTIs also can cause delirium in older people, resulting in a sharp decline in mental abilities that triggers disoriented thinking.

“Up to one-third of elderly patients hospitalized with UTIs can experience some degree of confusion and reduced awareness of their surroundings,” said Shouri Lahiri, MD, director of the Neurosciences Critical Care Unit and Neurocritical Care Research at Cedars-Sinai and senior author of the study. “Delirium affects millions of patients a year in the U.S., contributing to longer hospital stays, long-term cognitive problems and increased mortality. Delirium can be a tipping point from which patients never fully recover. This is well established. What is less well established is why this is happening.”

To better understand the specific biological mechanisms behind UTI-associated delirium, Lahiri and colleagues observed laboratory mice with and without UTIs in specially designed mazes. In an arena where the animals could move about freely, uninfected mice spent more time in the center of the chamber. Those with UTIs huddled in the periphery, suggesting they had higher levels of anxiety, a common symptom of delirium.

In a Y-shaped maze with three arms to explore, uninfected mice tended to explore all three arms, while mice with UTIs kept returning to the same one, suggesting a lapse in short-term memory, another feature of delirium.

The investigators also observed structural changes in the brains of mice with UTIs.

In a previous study led by Lahiri, published in February in the American Journal of Respiratory Cell and Molecular Biology, investigators found a connection between ventilator-induced lung injury and delirium. Lahiri and colleagues theorized that in both cases this was because of the reaction of IL-6, which helps regulate immune response, to the lung injury or the UTI.

“Occasionally, when the response of IL-6 is excessive, our research indicates that there can be brain injury,” Lahiri said. “IL-6 induces changes within the neurons that our studies connected with delirium-like behavior. This is the first time this type of structural and functional change has been demonstrated. We’ve now shown two distinct models of this connection, one non-infectious and one infectious.”

In the current study, when investigators treated some of the infected mice with antibodies that blocked the effects of IL-6, the delirium-like behavior of those animals resolved. “Treatment with anti-IL-6 antibody in the UTI group normalized all the brain changes, both structural and functional,” Lahiri said. “A wealth of studies have shown a link between IL-6 and delirium, but only this study and our previous study have shown that IL-6 may play a direct pathological role in delirium.”

If symptoms are treated early, he added, full recovery is possible, and the next step is to design clinical trials with anti-IL-6 antibodies as a treatment for patients with UTI-induced delirium.

“Dr. Lahiri and his team have built a research framework with implications far beyond this study,” said Nancy Sicotte, MD, chair of the Department of Neurology who holds the Women’s Guild Distinguished Chair in Neurology at Cedars-Sinai. “Building on these efforts could improve outcomes for many of our patients.”

Lahiri believes the model he and co-investigators created could be used to study delirium in other conditions associated with increased incidence of UTI. These include those with pre-existing neurologic disorders like Alzheimer’s disease, Parkinson’s disease, stroke and multiple sclerosis where delirium can be hard to distinguish from the underlying disease but is important to treat.

“A huge population stands to benefit from these investigations,” he said. “We’re looking to apply this model to these other systemic disease conditions and states where the brain dysfunction caused is potentially reversible.”

Funding: This study was supported by National Institutes of Health/National Institute on Aging Grant R03AG064106, the American Academy of Neurology Institute and the F. Widjaja Foundation.

Read more on the Cedars-Sinai Blog: Alzheimer’s and Dementia FAQs

Although a Google search shows some 82,000 recent news stories about dry drowning, Stephen Robert, MD, associate director of the Pediatric Intensive Care Unit at Cedars-Sinai, says the term is greatly misunderstood.

"The term 'dry drowning' refers to an acute lung injury caused by water aspiration that would develop over minutes to hours after exposure and could progress to respiratory failure," said Robert. "However, risk of death from this type of submersion injury in the absence of loss of consciousness at the scene would be exceedingly low compared with death from an actual, real-time drowning—so prevention of water accidents, not intensive observation of a child who looks well after a little sputtering, deserves the real attention."

Small children may not be able to communicate what they are experiencing after a submersion injury, so after a water scare, it makes sense for parents to watch for fast or labored breathing and to seek medical attention if there are any concerns. Signs of difficulty breathing may include unusually fast breathing, the appearance of the chest "sucking in," poor skin color, changes in mental status, decreased oral intake or coughing. If these symptoms appear or begin worsening, parents should seek medical attention immediately.

But Robert stresses that a delayed onset to serious respiratory problems is rare and says parents should instead focus on drowning prevention by watching intently whenever their child is around water.

"In almost every drowning case, parents report that the responsible adult only turned away for a minute," said Robert. "And unfortunately, it's likely true, but that's all the time it takes for a child to lose consciousness."

Robert answered some common questions he hears from parents:

What age group is most at risk for drowning? Drowning is the leading cause of death by injury in children aged 1 to 4. “That's because these toddlers are mobile and innately curious, naturally exploring their environment and typically unable to swim. But older children and even teenagers also are at risk of drowning, especially if alcohol is involved,” Robert said.

Where can drownings happen? Toddlers can drown in as little as 1 or 2 inches of water. "People know to watch children around pools, beaches and lakes, but they are often less vigilant about smaller hazards like bathtubs, toilet bowls, inflatable kiddie pools, flooded ditches or bird baths," Robert said.

What are your top water safety tips for parents? Small children are extremely vulnerable and require intensive supervision. "Water safety is a hands-on experience—which means parents should remain physically present throughout their child's bath time and be close enough to touch a child in the pool who isn't yet a strong swimmer," Robert said.

Robert also recommends exposing small children to water, and to let them get a little water in their noses so they develop a healthy respect for the water and will be more likely to avoid it without a parent in close proximity. It's also critical to teach small children to float on their backs, suggested Robert.

"And most important—if you have a swimming pool, fence it in and keep it locked securely," said Robert.

What other tips do you want parents to know? "All too often when 'everyone' is watching the kids, no one is. Designate a water-safety supervisor whose sole responsibility is to watch the children, then alternate between responsible, sober adults every 20 minutes," Robert said.

He also advises taking multiple precautions. For example, if your toddler cannot swim, equip them with a flotation device, get in the pool yourself, install a gate around your pool, designate a sober water-safety supervisor, enroll your children in swim lessons and talk to them about the importance of never going near a pool without an adult.

"These extra levels of protection can mean the difference between life and death for your toddler," Robert said.

Read more on the Cedars-Sinai blog: Know the Signs of Water Distress

“Calcium is a token to get different body organ systems to work, and it forms and maintains healthy bones, since most calcium is stored in your bones,” Kang told Runner’s World. “Calcium also helps your heart muscles pump and transmits signals to your nerves so your muscles contract.”

Based on guidelines from the Institute of Medicine, part of the National Academies of Sciences, Engineering and Medicine, adults should get 1,000 milligrams (mg) of calcium per day. However, Kang suggests that if you’re pregnant or breastfeeding, you should increase your daily intake to 1,200 mg to 1,300 mg. For context, milk contains 305 mg of calcium per cup, Parmesan cheese has 331 mg of calcium per ounce and 8 ounces of plain, full-fat yogurt has 274 mg of calcium.

If individuals are low on calcium for an extended period, it can lead to weakened bones and an increased risk of fractures. Although most people will not notice immediate symptoms of a calcium deficiency, but the longer the deficiency lasts, the more severe the symptoms will become.

The first common symptom is experiencing frequent muscle cramps. Because calcium helps with muscle contraction, low levels of the mineral means you might experience more muscle cramps than usual, Kang says, specifically in your back and legs. Other symptoms include brittle fingernails, bone-related injuries, irregular heartbeat and tingling in arms and legs.

Click here to read the complete article in Runner’s World, including how to get more calcium in your diet.